The present invention relates generally to computer workstations which are connected for information interchange with host or mainframe computer systems; more particularly, the invention relates to a method and apparatus for controlling the displayed position of entry field data on certain computer workstations by processing keystroke operations at a workstation control interface without participation of the host processor to which the workstation is connected. Further, the invention enhances the user interface associated with certain types of entry fields displayed on workstations.
In any typical prior art system utilizing a host processor, workstation control interface, and workstations, wherein the workstations are utilized for user interaction and access and the host processor is utilized for running application programs, the host processor provides certain fundamental information. For example, the host processor may generate a data stream containing information to be displayed on a workstation screen, and information for controlling the presentation and position of the data on the screen. In the case of a programmable workstation (PWS), the host processor data stream is sent directly to the workstation and is processed internally in the workstation, which itself contains sufficient internal memory and program data to directly control the interaction with the display screen and keyboard. In the case of a dependent workstation (DWS), the host processor data stream is sent to a workstation controller (WSC), and the WSC provides the internal memory and control for directly controlling the display screen of the DWS. In either case, the host processor-constructed data stream is received by a workstation control interface (hardware and/or software), and the workstation control interface processes the data stream. The workstation controller may poll attached DWS workstations to determine whether a keystroke should be recognized or whether any of a predetermined number of commands from the workstation controller have been processed.
Although a PWS terminal is of considerably more sophisticated design than a DWS terminal, when it is used in an environment where a host processor executes applications programs and merely utilizes the PWS terminal for DWS-like operator/user interface, the PWS terminal suffers from most of the same limitations as a DWS terminal. For example, each time a display panel is to be changed on the screen of either type of terminal as a result of user interaction, the host processor creates the panel description, and presentation, and constructs a data stream for transmission to the terminal. For convenience herein, reference will be made primarily to DWS terminals throughout, it being understood that the uses and advantages of the invention are equally applicable to both types of terminals. Where reference is made herein to workstation controllers (WSC), it should be understood that such controllers are associated with DWS terminals, and PWS terminals do not utilize workstation controllers except for basic connectivity. PWS terminals communicate directly with the host processor through suitable I/0 communications controls, but PWS devices have internal logic which effectively performs the same workstation control interface functions as are performed by workstation controllers.
In the course of communicating with remote terminals via a workstation control interface, the host processor application program and/or display data manager program assembles data for transmission to the remote terminal for constructing display panel images. Among the display panel constructs which have been uniformly adopted is the entry field, which is understood to be a continuous field reserved for entry of information by the operator through the operator keyboard. The size and position of entry fields are defined by the host applications program and/or display data manager program, and entry fields are usually highlighted on the display screen by regions of underlining, to provide an indication to the operator concerning the position and width of an entry field. If an entry field is longer than the space available on a single line of panel display, the entry field will wrap to the next line of panel display to provide the necessary character columns deemed to be relevant to the particular entry field input information. A single panel display may have more than one or two entry fields, and each entry field may be accessed by cursor positioning to the initial character position of the entry field. For purposes of the present invention, it is convenient to define a variant form of entry field; namely, the "continued entry field." A continued entry field may occupy any position on a display panel, but when a continued entry field extends from one display line to the next display line it does not necessarily wrap to the leftmost position of the second display line. A continued entry field may contain a plurality of individual segments, wherein each segment may be uniquely positioned on the display panel, not necessarily in the form of a continuous line extending from the last column of one line and wrapping to the first column of the next subsequent line. The segments of a continued entry field are linked together according to the teachings of the present invention, and multiple continued entry field segments are processed as a single entry field rather than as a plurality of discontinuous entry fields.